[CP2K:3975] CP2K PM6 result does not consistent with MOPAC PM6

hut... at pci.uzh.ch hut... at pci.uzh.ch
Mon Aug 20 10:00:32 CEST 2012


Hi

sorry first for my mixup of Ag and Au.
I made a couple of quick checks. It seems that there are
at least two minima within LSD PM6 for AgO.
If you start with a bond distance of 1.0 you end up
at a bond of 1.90 and Hf=134kcal. If you start with
a bond distance of 3.0 you converge to d=2.03 and Hf=97.8kcal.

Maybe you can map out the potential energy curve and see if there
are any more minima.

regards

Juerg 

--------------------------------------------------------------
Juerg Hutter                         Phone : ++41 44 635 4491
Physical Chemistry Institute   FAX   : ++41 44 635 6838
University of Zurich               E-mail:  hut... at pci.uzh.ch
Winterthurerstrasse 190
CH-8057 Zurich, Switzerland
---------------------------------------------------------------

-----cp... at googlegroups.com wrote: -----
To: cp... at googlegroups.com
From: Bharat Sharma 
Sent by: cp... at googlegroups.com
Date: 08/17/2012 07:52PM
Subject: Re: [CP2K:3975] CP2K PM6 result does not consistent with MOPAC PM6

Dear Hutter,

Thank you for your reply.

Au parameters are correct as reported in paper. I started the calculation with the Ag-O distance of 2.03Angstrom both in CP2K and MOPAC (simply same initial geometry). The uptimized bond length of Ag-O from CP2K is 1.90 A where as from MOPAC is 2.03A which is consistent with PM6 results in "AM1* parameters for palladium and silver, J Mol Model (2011) 17:2585–2600)". 

I did not one shot energy calculation with Ag-O distance of 2.03A in CP2K but the heat of formation is 135.7645 kcal/mole but from MOPAC is 98.21kcal/mole.

I did the test calculation of AgH+, Ag(NH3)4+, AgF from both in CP2K and MOPAC but results are fairly similar( error ~ or less 1 kcal/mole). 

In all test calculations, the initial geometries for CP2K and MOPAC are same.

Thank you.

Sincerely,
Bharat Sharma

 On Fri, Aug 17, 2012 at 7:36 AM,  <hut... at pci.uzh.ch> wrote:
 Hi
 
 I quickly checked, the Au parameters should be correct.
 Can you make some additional tests? For example is the optimized
 geometry the same? What is the difference in energy for a given
 geometry?
 Are the results correct for other molecules containing these
 atomic types?
 
 regards
 
 Juerg Hutter
 
 --------------------------------------------------------------
 Juerg Hutter                         Phone : ++41 44 635 4491
 Physical Chemistry Institute   FAX   : ++41 44 635 6838
 University of Zurich               E-mail:  hut... at pci.uzh.ch
 Winterthurerstrasse 190
 CH-8057 Zurich, Switzerland
 ---------------------------------------------------------------
 
 -----cp... at googlegroups.com wrote: -----
 To: cp... at googlegroups.com
 From: bharat
 Sent by: cp... at googlegroups.com
 Date: 08/16/2012 04:21PM
 Subject: [CP2K:3974] CP2K PM6 result does not consistent with MOPAC PM6
 

 Dear Experts,
 
 I did the semiempirical calculation with PM6 for the small system of AgO. CP2K gives the Heat of formation of 134.9850424864 kcal/mol whereas MOPAC gives the 98.21606 kcal/mol. The experimental Heat of formation is about 53.0 kcal/mol.
  
 I do not know why CP2K can not reproduce the same result as MOPAC.
 
 Can anybody help me to figure out, what wrong is going on in CP2K calculation.
 
 My simple input is following.
 
 Thank you in advance.
 
 Sincerely,
 Bharat Sharma
 
 &FORCE_EVAL
   METHOD Quickstep
   &DFT
    CHARGE 0
    LSD T
     &QS
       METHOD PM6
       &SE
        ANALYTICAL_GRADIENTS F
       &END
     &END QS
     &SCF
       SCF_GUESS ATOMIC
     &END SCF
   &END DFT
   &SUBSYS
     &CELL
       ABC 20.0 20.0 20.0
       PERIODIC NONE
     &END CELL
     &COORD
  O                 -2.48815585    0.31201747    0.00696372
  Ag                -4.60495278    0.41447825    0.06239400
     &END COORD
   &END SUBSYS
 &END FORCE_EVAL
 &MOTION
   &GEO_OPT
    MAX_ITER 5000
   &END GEO_OPT
 &END MOTION
 &GLOBAL
   PROJECT AgO
   RUN_TYPE GEO_OPT
 &END GLOBAL
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